It is a condition whereby the articular cartilage which lines the shoulder joint becomes worn out. This is a degenerative
process and occurs more common with increasing age. It can sometimes affect young patients as well especially following
injuries which have caused cartilage damage, or disruption of the blood supply to the head of the humerus, otherwise known
as avascular necrosis. This is often seen following radiotherapy or long term steroid therapy

Radiographic image of advanced avascular necrosis of humeral head

How does arthritis progress?

As sections of the cartilage are worn away, bare bone is exposed in the ball and socket joint. As the bone surfaces rub
against each other, this produces friction with subsequent grating, pain and stiffness. In addition, bony spurs may form
at the edge of the joint and fragments of loose bone or cartilage may appear in the joint space.

Radiographic image of advanced osteoarthritis in the shoulder with prominent bone spurs and loose bodies

What types of arthritis are there in the shoulder?

Osteoarthritis

Rheumatoid arthritis

Rotator cuff tear and arthritis

Arthritis of the acromioclavicular joint – this is completely
different from the above 3 types of arthritis and the treatment of isolated acromioclavicular arthritis is by key
hole surgery which reliably produces excellent results with rapid recovery.

Patients with shoulder arthritis usually develop pain and stiffness. The pain is often worse at night, especially when
trying to sleep on the side. Subtle degree of stiffness may be noticed on a day to day basis with inability to perform
tasks which involve shoulder rotation such as blow drying the hair or undoing the bra from behind.

What are the treatment options?

Physiotherapy

Steroid injections into the shoulder joint

Arthroscopic debridement (Key hole surgery – washout)

Shoulder replacement

What types of shoulder replacement are there?

The shoulder replacement can be done in the form of a surface replacement whereby the irregular humeral
head is ‘smoothened’ out and a metallic ‘mushroom’ type cap placed over the humeral head. Traditionally, shoulder replacements
were done using a stemmed implant that goes down the shaft of the humeral bone and is still indicated
in selected cases. Finally, in patients with severe rotator cuff rupture and arthritis, and perhaps those with a previous
unsuccessful shoulder replacement, a reverse shoulder replacement might be indicated. This is similar to the conventional
type of replacement except that the ball and socket positions are reversed. By placing the prosthetic socket in the humerus
of the upper arm and the ball in the glenoid cavity, the biomechanical function of the shoulder is greatly improved.

How long is the recovery usually following a shoulder replacement?

With advances in technology and minimally invasive techniques, most patients will stay one night in hospital although
some do go home on the same day. Following surgery, you will be asked to wear a sling usually for about 2 to 3 weeks until
the muscles heal. Physiotherapy will then be needed to regain the movements and build up the strength in the arm.

Types of shoulder replacements - Images

Resurfacing of humeral head (ball)Stemmed Shoulder replacement

Glenoid (this is the artificial socket for
the shoulder joint)

Reverse ball and socket type of shoulder
replacement

Radiograph of cuff tear
arthropathy showing evidence of arthritis with deficient rotator cuff After a reverse polarity shoulder replacement
– note that the ball and socket parts of the prosthesis have now been ‘switched over’

Biomechanical considerations of the normal and rotator cuff deficient shoulders and the reverse shoulder
prosthesis